- 1 1 The Signal To Noise Ratio Of A Pin Photodiode Is Given By Snr B 2eb 1 1 4ktb R Biz A Nrz Pulse Modulated S 1 (39.47 KiB) Viewed 36 times
1.1. The signal to noise ratio of a pin-photodiode is given by: SNR B 2eB(1, + 1) + 4kTB R + Biz A NRZ pulse modulated signal with a bit rate, BT of 150 MB/s is transmitted over 50 km long single mode fibre link. To ensure the required bit-error-rate for the system, the signal-to noise ratio at the receiver must be 26 dB. The receiver is a transimpedance amplifier with an open loop gain of 200. The average amplifier noise current is 2.2 p./(Hz)"?, the amplifier input resistance is 10 kohm and the feedback resistor is 10 kohm. The photodiode has a junction capacitance of 7 pF. 1.1.1. Calculate the minimum photocurrent for the diode to maintain the required SNR. (12) 1.1.2. Determine if the maximum bandwidth for the receiver and amplifier is larger than the required bandwidth. (5) 1.1.3. Find the shot noise limited current for the detector. (3)